Most modern leathers are "drum dyed" meaning it is artificial coloring manufacturer applies a "secret sauce if you will." Also means that most gloves with lining also offer limited protection from direct contact with leather. I have worn unlined cowhide, goat, kangaroo and deerskin leather gloves and experienced the problem only once with cheap Pakistan one...over many-many years as summertime gloves...yep wear 'em 'til they almost stand on their own, so it must be a manufacturer discretion thing.